Les Houches

This is an old revision of the document!

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Modifications: (19-Jun) - Removed end blocks - Added function arguments (e.g arg1, arg2,..) - Renamed SR to CUT - Inheritance explicitly defined by key 'contains' - Changed cut language to select/reject

Part I: Preamble (define detector objects, variables)

The idea is to write a plain text file that can be read easily into xml if needed (and hence universally readable). The name of the block become sthe xml tag. Anything that follows is turned into attributes. e.g. “name ATLAS” inside the block becomes <experiment name=“ATLAS”>. Anything inside the block starting with “#” is added as a comment, i.e. the first block below automatically converts to

<analysis name="ATLAS-2014-XXX" publication="JHEP11(2014)118" cme="8.0" lumi="20.0" description="Details about analysis">

There are five types of pre-defined blocks – detectorobj (defines reconstructed objects), function (defines functions that act on these), cut (blocks of cuts), SR (contains all cuts for a particular signal region) and results (for giving numbers). Besides this, the user can define whatever they want – e.g. here, “analysis” gives extra info, and “table” gives a way to provide tables or digitised histograms.

For any block, a link to code or external documentation can be provided. We can also include a MCsamples block to document the programs used to generate signal and background samples.

When a block inherits the properties of other blocks (e.g. medium electron inherits from loose), the names of those can be added after the name of the current block.

detectorobj elec_m elec_l

So here is the schematic for implementing the first signal region in the paper:

analysis
  # Details about experiment 
  name ATLAS-2014-XXX
  publication JHEP11(2014)118
  cme 8.0
  lumi 20.0
 
detectorobj jet
  # detectorobj are lists of objects of same type
  # <detectorobj type="jet" ... >
  # Some human readable definition goes here; we assume sorted by pt
  algorithm anti-kt
  R 0.4
  ptmin 20
  etamax 2.5
  pileup_sub _link_
  # Can provide code and/or link to writeup with details of implementation
  code _code_link
  doc _link_to_file_with_details	
 
function isolation 
  # Human readable description: takes 2 arguments; returns (sum of pT in cone of 0.1 around
  # electron)/(pt of lepton) takes in lepton and conesize
  arg1 detectorobj
  arg2 conesize
  code _code_link
  doc _link_to_file_with_details	
 
function overlap_removal 
  # takes in jet list and lepton, calculates based on recipe
  arg1 detectorobj-list
  arg2 detectorobj-list
  code _code_link
  doc _link_to_file_with_details	
 
detectorobj elec_l
  # Can provide code and/or link to writeup with details of implementation
  cut isolation<0.1
  cut overlap_removal
  code _code_link
  doc _link_to_file_with_details	
 
detectorobj elec_m 
  # electron-medium inherits from loose.
  # Can provide code and/or link to writeup with details of implementation
  contains elec_l
  code _code_link
  doc _link_to_file_with_details	
 
detectorobj lep 
  # lep inherits from medium electrons or muons
  contains elec_m 
  contains mu_m
end detectorobj
 
detectorobj met
  # Can provide code and/or link to writeup with details of implementation
  code _code_link
  doc _link_to_file_with_details	
 
trigger e_trig
  # Human readable info
  # Each signal analysis will need atleast one trigger to be satisfied
  # Can provide code and/or link to writeup with details of implementation
  eff 0.8
  code _code_link
  doc _link_to_file_with_details	
 
trigger m_trig
  # human readable info
  eff 0.8
  code _code_link
  doc _link_to_file_with_details
 
trigger met_trig
  # human readable info
  eff 0.8	   
  code _code_link
  doc _link_to_file_with_details
 
function pt 
  # p_T is a function (wrapper) that takes two inputs (1) name of list
  # of detectorobj and (2) the index in that list.  E.g. pt(jet2) =
  # pt(jet(2)); pt(elec_tight(1)) = pt(elec_t,1) In principle, all
  # common p(), eta(), phi() etc. need not be explicitly defined, this
  # is just an example
  arg1 detectorobj  
  code _code_link
  doc _link_to_file_with_details
 
function mt 2
  # mT requires one lepton and met i.e. mt(lep(1),met)
  code _code_link
  doc _link_to_file_with_details
 
function mt2 3
  code _code_link
  doc _link_to_file_with_details
 
function b-tag 1
  # takes in a jet and returns whether it is b-tagged
  eff 0.7
  code _code_link
  doc _link_to_file_with_details
 
function select 
  # select(listname, criterion)
  # e.g. select(jet, b-tag) returns number of objects (i.e. jets) give
  # true for the test (i.e. b-tag).  Should be made a global function like pT?
  arg1 detectorobj-list
  arg2 function
  code _code_link
  doc _link_to_file_with_details
 
detectorobj hadtop
  # Define hadtop 
 
function deltaR 2
  # takes in two objects; returns deltaR
 
detectorobj bjet
  #
  eff 0.7
  code _code_
  doc _doc_link_
 
function HT
  code _code_
  doc _doc_link_
 
function metBYsqrtHT
  # returns MET/sqrt(HT) 
 
function delPhi 2
  # returns minimum delta phi between objects

PART 2: uses the objects defined above to define the signal regions

cut cleaning
  # List of preselection cuts: Give human readable descriptions (for
  # your experimental collaborators) and efficiency for theorists (if applicable)
  code _link_to_code
  doc _link_to_doc
 
cut preselect
  # Pre-selection cuts
  eff 0.95
  trigger trigger_e.OR.trigger_mu.OR.trigger_met
  select pt(lep(1))>25
  reject size(lep)>1
  select size(jet)>2
  select met>100
 
 
cut tN_diag
  select preselect
  select size(jet)>4
  select pt(jet,1)>60
  select pt(jet,2)>60
  select pt(jet,3)>40
  select pt(jet,4)>25
  select mt(lep(1),met)>=60
  select m(hadtop)>=130
  select m(hadtop)<=205
  reject size(tau)>0
  select deltaR(bjet(1),lep(1))<2.5
  select metBYsqrtHT>5
  select delPhi(jet(1),met)>0.8
  select delPhi(jet(2),met)>0.8

Part 3: Present results of the analysis. Give numbers, exclusions, digitised histograms, link to plots, etc.

MCsamples
  # Human readable info regarding what programs were used to make what
  # sample suggested format: Signal program extra details (extras are
  # stored in description for xml
  signal Sherpa1.4.1 stop-pair
  background POWHEG ttbar mtop = 172.5 NLO
  doc _link_to_file_with_details
 
result tN_diag
  exp_sig
  stat_sig
  sys_sig
  exp_bg
  stat_bg
  sys_bg
  obs
  s95
  table data1
 
table data1
  # Not real data in example; could be used to provide histograms/tables/likelihoods
  bins nn
  data xlabel ylabel yerr 
   1.0 2.0 1.0
   2.0 1.0 1.0
   3.0 10.0 1.0
   4.0 15.0 1.0